1. Field of the Invention
The present invention relates to an image forming apparatus and method, and more particularly to an image forming apparatus and method in which a group of ink micro-particles (ink mist) is generated by ultrasonic waves so as to record images by means of the ink mist.
2. Description of the Related Art
Japanese Patent Application Publication No. 8-104004 discloses an ink mist type of image recording apparatus (ink mist printer) which records images by generating a flow of ink mist (very fine ink particles) by means of ultrasonic vibration, and depositing this ink mist onto a recording medium as a group (cluster).
In Japanese Patent Application Publication No. 8-104004, in order to create ink mist efficiently, a piezoelectric substrate serving as a vibration source has a concave on the side facing the ink ejection port, at least at an electrode installation region. However, if the mist is ejected to form dots on a recording medium in an overlapping fashion at high speed by using the mist spraying type of recording head, then deposition interference occurs between the formed dots, the dot shapes are disrupted and color mixing may arise between the dots, and therefore a high-quality image cannot be obtained.